Activity of IFN-gamma in experimental Leishmania infantum murine visceral leishmaniasis.

The effect of recombinant interferon-gamma (rIFN-gamma) on Leishmania infantum infection was investigated in vivo. BALB/c mice were injected intravenously (i.v.) with 10(7) promastigotes of Leishmania infantum. rIFN-gamma, 10(6) U given intraperitoneally (i.p.) daily on 3 consecutive days or 4 times on alternate days from day 7 (d7) post infection, had no detectable effect on the parasite burdens in liver, spleen, and lungs as compared to untreated mice. However rIFN-gamma enhanced the activity of Glucantime (50 mg/kg/d intraperitoneally for 7 days) in the liver and in the lungs. The additive effect of rIFN-gamma was still observed at day 30 post-infection, i.e. 15 days after cessation of therapy. By contrast the combination of the two drugs had no activity against splenic parasites.